Dupedit is currently a tool for finding/verifying duplicate files. The builtin help text should be self explaining.

Dupedit is smart:
You can never fool dupedit to compare a file against itself. Hardlinks, symlinks and multiple paths to the same file are revealed by their common device and inode numbers and treated/displayed as multiple instances of the same file. When you know how to interpret this, not even `mount --bind` can make unique files look like duplicates.

Dupedit is fast:
Dupedit compares files not by checksums, but directly in units of an intmax_t (the number of bits in your processor) at a time. Internally, dupedit will not read an intmax_t more than necessary from each file, and never read a file more than once. In reality, your system will likely have a strategy to read larger continuous chunks at a time. I'm just Only files of equal size gets compared, of course.